The invention relates to door hinges with integrated locking devices, particularly for doors of motor vehicles having a door hinge with an integrated locking device for yielding positioning of a door at predetermined angles relative to a frame comprising:
a first hinge part having a base plate with integral, upstanding legs;
a bending spring;
a second door-side hinge part having plural rollers attached thereto in a rotatable manner;
a hinge shaft for rotatably securing the second hinge part to the first hinge part; and
wherein one of the plurality of rollers deforms the bending spring when the second hinge part is swivelled relative to the first hinge part.
Doors of motor vehicles are normally each fastened by two hinges on the frame of a motor vehicle and generally have at least one locking device which permits the opening or closing of the door against a predetermined resistance. The hinge maintains the door at certain preferred positions during the opening or closing and provides resistance to movement so that the doors can be moved only with an increased expenditure of force.
U.S. Pat. No. 4,532,675 discloses a door hinge with an integrated locking device by which a door of a motor vehicle can be held in an open position. This hinge contains first and second hinge parts which are swivelled relative to one another about a joint axis of rotation. The integrated locking device contains a bending spring on a first hinge part and a roller on a complementary second hinge part. The bending spring is mounted in a prestressed manner on a base plate of the first hinge part and is bent away from the base plate. In order to ensure a sufficient spring travel at the point at which the bending spring interacts with the roller, the bending spring must be located from the base plate by a large distance. Thus, the distance of the roller on the second hinge part and the distance of the axis of rotation from the plane of the base plate of the first hinge part will also become large. The mounting of the bending spring under prestress requires high machining expenditures, particularly when the locking device is to be retrofitted after the door is mounted. The free length of the bending spring is relatively short so that bends occur over a short distance which results in a susceptibility to breakage of the bending spring. This prior art does not contain an intermediate position from which a half-opened door can be moved with an increased expenditure of force.
European Patent Document EP-A 92 110 525.0 shows a door hinge for a motor vehicle with an integrated locking device which can be held in two positions or different angles during an opening or closing. The locking device contains a pressure spring on a first hinge part and two rollers on the complementary second hinge part. The spring is bent about a base plate and is bent away from this base plate. This arrangement is expensive to produce because of its complicated spatial structure. The part of the pressure spring bent away from the base plate, as in the above-mentioned U.S. patent document, results in an increased distance of the roller. This requires an increased distance of the joint axis of rotation from the plane of the base plate from which the forces are transmitted from the door to the door hinge. This distance also increases the amount of the torque on the hinge parts, when large forces occur on the door, as well as a large tension in the hinge parts. Thus, such a design requires sufficient fatigue strength which can be achieved only by expensive high-strength materials or very large material thicknesses. The elastic length of the pressure spring of this known door hinge is limited by the dimensions of the base plate on which the pressure spring is supported.
These known door hinges have springs, whose elastic lengths are limited, which results in unfavorable spring characteristics and to increased susceptibility to breakage. The relatively large distances of the common axes of rotation of the hinge parts, from the mounting and force introduction points on the door, cause the forces introduced by the doors to produce high torque on the hinge parts. Since, with growing safety requirements which, for example, increase the demands for protection against a lateral impact, the demands for strength of door holding devices are also increasing. The ability to avoid high torques by an optimized constructive design of the hinge parts gains in significance. The springs according to the above-mentioned state of the art have complicated spatial structures which result in high manufacturing costs for the bending springs.
With narrow space conditions between the door and the frame of the motor vehicle, the above-mentioned door hinges are difficult to mount. In the situation with a mounted door, the locking devices of these known door hinges cannot be retrofitted separately, since the necessary high prestresses cannot be applied to the springs. So, for these known door hinges, it is most difficult or impossible to use them for spare parts or in replacement situations.
These known door hinges are made of milled and/or stamped steel profiles which are expensive to manufacture so that, for small orders, these known door hinges cannot be used or are not economical to use.
It is therefore an object of the instant invention to provide a door hinge with an integrated locking device which has a high stability and fatigue strength while mounting characteristics are favorable and the manufacturing costs are low.
This object is achieved by a door hinge with an integrated locking device for yielding positioning of a door at predetermined angles relative to a frame comprising: a first hinge part having a base plate with integral, upstanding legs; a bending spring; a second door-side hinge part having plural rollers attached thereto in a rotatable manner; a hinge shaft for rotatably securing the second hinge part to the first hinge part; wherein one of the plurality of rollers deforms the bending spring when the second hinge part is swivelled relative to the first hinge part; wherein the bending spring is configured to have three U-shaped sections, a first U-shaped section comprising a transverse section and two parallel legs adjoining the transverse section at an approximate angle of 90.degree., a second U-shaped section connected to one of the parallel legs and configured with a 180.degree. bend and an end leg extending therefrom, and a third U-shaped section connected to the other parallel leg and configured with a 180.degree. bend and an end leg exending therefrom; wherein the parallel legs of the bending spring extend essentially parallel to sides of the base plate of the first hinge part; and wherein the bending spring is mounted to the first hinge part in an unstressed condition.
It is also advantageous if the bending spring extends in a single plane; if the end legs of the bending spring are parallel to one another in grooves in the base plate, and the two parallel legs are spaced farther from one another than the end legs and centered around the base plate; if the second hinge part is equipped with at least two rollers, which are each rotatably disposed therein; if the second hinge part has stops which contact the upstanding legs of the base plate when the door is completely open; if the first hinge part is made of any one of plastic or sintered metal; if the second hinge part is fixedly clamped by means of a conical hinge shaft in a bore with a cone of the first hinge part; if the ends less the bending spring are surrounded by self-lubricating metalloplast bushes in grooves on the first hinge part; if the bending spring is detachably connected to the base plate of a holding device; or if the base plate has grooves for receiving bushes holding the ends of the bending spring and the edges of the grooves are deformed after insertion of the ends of the bending spring, surrounded by bushes, so that the bending spring is fixedly held in the grooves.
The door hinge with the integrated locking device is equipped with a bending spring which is guided such that relatively large "free lengths" occur between bearings on ends of the bending spring in an essentially plane base plate of a first hinge part and with the introduction of force from rollers of a second hinge part. When the second hinge part is rotated relative to the first hinge part, forces and deformations can be carried away by the bending spring along relatively long paths which results in an improved springing action and a longer durability of the bending spring. The characteristic shape of the bending spring permits a compact construction of the door hinge so that small installation irregularities can be compensated for. Therefore, the rollers on the second hinge part and, hence, the common axis of rotation of the hinge parts can be mounted at a reduced distance with respect to the plane of the base plate. The overall spring force of the bending spring is predominantly the result of bending of a transverse section, the legs and the free ends of the bending spring and, to a negligible extent, on the torsion in bends of the bending spring. The bending spring can be fastened on the first hinge part without prestress, whereby the retrofitting of locking devices on already mounted doors is facilitated.
The bending spring of the door hinge with the locking device is preferably flat since the manufacturing of flat bending springs requires a lower cost and is therefore more reasonable with respect to the cost of manufacturing spatially curved springs. The flat bending spring promotes a compact construction of the door hinge.
The arrangement of the legs of the bending spring in parallel to two sides of the base plate and the arrangement of a transverse section of the bending spring which is in parallel to one side of the base plate and closely adjacent the first hinge part permits a very compact construction of the door hinge with an integrated locking device.
By utilizing two rollers, three positions of the door can be established: a first position in which the door is closed; a second position in which the door takes up a defined center position; and a third position in which the door is fully opened. By utilizing more rollers than in the preferred embodiment, correspondingly more positions of the door can be established. The positions and geometries of the rollers determine the resistance forces on the vehicle door.
According to an advantageous development of the invention, the second hinge part is equipped with stops which, when the door is fully open, are placed against the legs of the base plate of the first hinge part and prevent a further open swivelling of the door caused, for example, by a gust of wind. According to the invention, in the position of the fully opened door, a stable condition will automatically occur because the bending spring will still be acting on one of the rollers, preferably the smaller roller, and will press the stops of the second hinge part against the legs of the base plate of the first hinge part.
A cast material can be used for the hinge parts and particularly the base plate which process requires lower tool costs for manufacturing and therefore permits the manufacturing of smaller piece numbers in a cost effective manner.
According to another advantageous development of the invention for a lift-off system, the hinge parts of the door hinge are connected with one another in an easily detachable manner. For mounting or demounting, the door must only be lifted in or out and will center automatically after the mounting. The lift-off system is-particularly advantageous for the installation of mounting systems, such as window lift mechanisms, loudspeakers, etc. into a vehicle door because, herein, the vehicle door is normally dismounted after being painted. The lift-off system permits a simple facilitated reinstallation of the vehicle door in the fabrication process without the requirement of a repeated adjusting of the vehicle door during the reinstallation. The mounting takes place in the so-called center catch position of the vehicle door in which the bending spring is not stressed.
In order to further improve the fatigue strength of the locking device of the door hinge, it may be advantageous to dispose the bending spring in a sleeve so that tensions, particularly at the edge of the bearing and the susceptibility to breakage of the bending spring are reduced. In principle, the bearing may be implemented without any sleeve.
According to a particularly advantageous development of the invention, the bearing of the bending spring is detachable so that the mounting of the bending spring is facilitated.
According to an alternative development of the bearing of the bending spring, the bending spring is secured to the base plate by deforming an edge of the base plate over the spring so that a firm securement is obtained with low construction expenditures and few component parts.
According to another advantageous development, the bending spring is held in an adjustable manner so that the locking device can be adapted to different requirements and vehicle models.
According to the invention, the rollers can be constructed of a self-lubricating material so that the rollers operate with reduced noise. Here, the shafts of the rollers should not be surrounded with a bearing material.
The door-side hinge part may be provided with a detachable mounting plate for fastening the door-side hinge part to a vehicle door.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.